This invention relates in general to devices for measuring the angular relationships between the various components of a vehicular drive train system. More particularly, this invention relates to an adapter for facilitating the measurement of the angular inclination of components having yokes secured thereto in such a vehicular drive train system.
In most land vehicles in use today, a drive train assembly is provided for transmitting rotational power from an output shaft of an engine/transmission assembly to an input shaft of an axle assembly so as to rotatably drive one or more wheels of the vehicle. To accomplish this, a typical vehicular drive train assembly includes a hollow cylindrical driveshaft tube. A first universal joint is connected between the output shaft of the engine/transmission assembly and a first end of the driveshaft tube, while a second universal joint is connected between a second end of the driveshaft tube and the input shaft of the axle assembly. The universal joints provide a rotational driving connection from the output shaft of the engine/transmission assembly through the driveshaft tube to the input shaft of the axle assembly, while accommodating a limited amount of angular misalignment between the rotational axes of these three shafts.
The relative angular relationships between the axes of rotation of the transmission output shaft, the driveshaft tube, and the axle assembly input shaft are important factors in the proper operation of the drive train system. For example, if the angle defined between the transmission output shaft and the forward end of the driveshaft tube is not approximately equal to the angle defined between the rearward end of the driveshaft tube and the axle assembly input shaft, torsional vibrations may be induced in the vehicle drive train system when rotated during use. Such vibrations can cause undesirable noise and, if not corrected, premature wear and failure of the components of the vehicle drive train system, including the transmission, the universal joints, and the axle assembly.
Accordingly, a number of devices have been developed for facilitating the determination of the relative angular relationships between the various components of the vehicle drive train system. One such device is the Anglemaster.RTM. inclinometer sold by Dana Corporation, the assignee of this invention. When disposed in an abutting relationship against a component of the vehicle drive train system, the inclinometer measures the angular inclination of the component relative to the horizontal. The relative angular relationship between any two components in the vehicle drive train system can be determined by individually measuring the angular inclination of each of the components using the inclinometer, then subtracting the two measurements to achieve the relative angular relationship therebetween.
It is usually quite easy to dispose the inclinometer in direct abutting relationship with the driveshaft tube in order to determine the angular inclination thereof. However, it has been found that it is sometimes difficult to move the inclinometer into abutting relationship with the output shaft of the transmission and the input shaft of the axle assembly. Each of these shafts is usually formed having a longitudinally extending splined portion having a yoke secured to one end thereof. Typically, the majority of the longitudinally extending splined portions are disposed within either the transmission or the axle assembly and, therefore, are not readily available for engagement by the inclinometer. Thus, it is known to dispose the inclinometer in abutting relationship with the yokes secured to such shafts in order to measure the respective angular inclinations thereof. In some instances, the yokes are formed having flat machined surfaces that are readily available for engagement by the inclinometer. However, such flat machined surfaces are not always precisely aligned with the rotational axis of the associated shaft, resulting in somewhat inaccurate measurements by the inclinometer. Furthermore, many yokes are not formed having such flat machined surfaces. Thus, it would be desirable to provide an adapter for facilitating the measurement of the angular inclination of such shafts in a vehicular drive train system.